Neural stimulation has been proposed as a therapy for a number of conditions. Neural stimulation may be delivered to modulate the autonomic system, which may be referred to as an autonomic modulation therapy (AMT). Examples of AMT include therapies for respiratory problems such as sleep disordered breathing, blood pressure control such as to treat hypertension, cardiac rhythm management, myocardial infarction and ischemia, heart failure (HF), and modulation of the cholinergic anti-inflammatory pathway. For example, therapies to treat epilepsy, depression, pain, migraines, eating disorders and obesity, and movement disorders may include stimulation of a vagus nerve.
For some therapies it is desirable to block or inhibit action potentials from propagating in nerve axons. Neural stimulation may be delivered to block nerve traffic. For example, kilohertz high frequency alternating current (KHFAC) or direct current (DC) may be used to block action potentials. However, both KHFAC and DC blocking has some limitations. For example, KHFAC blocks cause an intense burst of firing in the nerve when first initiated, which is likely to produce an uncomfortable sensation of that may last from milliseconds to more than 30 seconds. Additionally, DC nerve blocks are unsafe for the nerve for chronic applications because they deliver unrecoverable charge to the neural tissue.